Recently, many of my friends have gone to mainstream large Internet companies for interviews (Alibaba, JINGdong – Meituan), and they will send me some interview questions after the interview. Some of my friends easily got the offer, but some of them came to ask me the answer.

In fact, I really didn’t plan to write this article, mainly because MY memory is not very good, unlike some people with strong memory, after the interview, they can almost write down their conversations with the interviewer. After his initial interview, in addition to remember some of the knowledge points talked about, the specific content is basically forgotten, so write this article is actually very difficult.

However, there are too many people asking me lately. In order to avoid repeating the answer and save myself some energy, I simply reply here. To be honest, I can only vaguely remember the keywords of high concurrency, JVM, distributed and TCP/IP, but I can hardly remember the specific issues. And even if I did, and I told you, and you memorized, I still think it’s very unlikely that you’ll be asked the exact same question in an interview. And even if you’re lucky enough to be asked, it’s not necessarily a positive thing to memorize, because if the interviewer asks you more than one question, you might as well just say no. Here to tell you about large-scale Internet enterprises interview questions.

Let’s take a look at the interview materials I recorded:

First, Alibaba interview

Number one: What does Ali ask in the interview? (55 minutes)

01

1. What are the data structures that Java uses most in development?

2, Talk about your understanding of HashMap, basic implementation of the underlying principle, how HashMap to solve the collision problem?

Are these data structures thread-safe? If you say HashMap is thread-safe, then ask if you have a thread-safe map, and then ask the Conurren package.

3. Are you familiar with the JVM? A brief description of the class loading process. What does it do? GC and memory management are usually configured in Tomcat

4, then ask HTTP protocol, get and POST basic difference, then TCP/IP protocol, three handshake, window sliding mechanism.

5. Which databases are used in the development? What are the storage engines? Then asked me pessimistic lock and optimistic lock problem use scenarios, distributed cluster implementation principle.

6, then asked me the working principle of SpringMVC and Mybatis, have you read the underlying source code?

Two, jingdong Finance interview

02

1. Dubbo timeout retry; Distributed transaction and distributed lock (no negative deduction) 4. Distributed session setting 5. Execute an operation, the first 50 times are successful and the 51st time is failed a roll back all the first 50 times B Submit the 51st throw exception 7, JVM memory model 8, database vertical and horizontal split 9, MyBatis how paging; How to set up the cache; MySQL pagination 10, Familiar with IO? The difference between NIO and blocking and non-blocking 11. Distributed session consistency 12. Idempotent design of distributed interfaces

Iii. Meituan interview

03

1. Which project have you been familiar with recently? Figure 2. The ratio of the old JVM to the new one? What are the meanings of jstack, Jmap and jutil? How to troubleshoot JVM related issues online? 5. What are the specific meanings of the 5 parameters of the thread pool constructor method? 6. What if a sudden power outage occurs while a thread pool is processing services on a single machine? How to handle requests in processing and blocking queues? 7. What is the problem with using unbounded blocking queues? 8. How does the interface handle repeated requests? 9. What is the specific treatment plan? 10. How to ensure atomicity when changing shared variables? 11. Design an interface implementation class for external services to realize load balancing and sequential polling mechanism (considering concurrency) on the three hosts (1,2,3) (corresponding to different IP addresses).

conclusion

The above is to collect and share the interview questions of large Internet famous enterprises, and share them with you. I hope you can understand what is the interview questions of large Internet famous enterprises. If you feel the harvest, you can point a attention to collect and forward a wave oh, thank you for your support!

I have specially sorted out a lot of questions that can not be clearly explained by a few words. I have collected a set of BAT interview video collection on the Internet to answer these interview questions. In fact, the answer to many questions is very simple, but the thinking and logic behind it is not simple, to know the why and why, and some Java high concurrency, distributed, microservices, JVM, source code analysis and other technology videos are also shared in my Java backend technology group.

Welcome to work for one to five years of Java engineer friends to join the Java architecture development: 685167672 this group provides free learning guidance architecture information and free answers to questions you do not know can be raised in this group after the career planning and interview guidance